Anexvivocomparative study of occlusal and proximal caries using terahertz and X-ray imaging

Abstract

Objectives: To examine the effectiveness of terahertz (THz) pulsed imaging (TPI) in comparison to intraoral photostimulable phosphor late (PSP) and cone beam CT (CBCT) for the detection of dental caries ex vivo. Methods: Newly extracted 32 human permanent teeth surfaces (16 with caries and 16 without caries) were serially sectioned mesiodistally and imaged by using four image sets as follows: (1) CBCT; (2) PSP; (3) THz movie video; and (4) THz static images. All images were evaluated twice separately by two calibrated observers for the presence/absence of caries using a 5-grade rating/confidence scale. Weighted κ coefficients were calculated. Different image sets were compared with the histological gold-standard using the receiver operating characteristic and area under curves for each image set were compared using χ 2 tests, with a significance level of α = 0.05. Results: Intra-and interobserverκ-values for all image sets were almost excellent ranging between 0.777 and 0.988. Mean Az values of observers and readings were 0.898 for CBCT, 0.888 for PSP images, 0.853 for THz static images and 0.781 for THz video movie. No statistically significant differences (p > 0.05) were found between Az values for the different image sets. When observer scores were evaluated according to caries location again no statistically significant differences (p > 0.05) were found between Az values for the occlusal and proximal caries for the four image sets. conclusions: Terahertz pulsed imaging was found to be successful for the detection of dental caries ex vivo.

THz Pulsed Imaging in Biomedical Applications

“…TPI has been found to be an interesting technique for dental tissue (enamel, dentine and pulp) discrimination because refractive index differences enable the three tissue regions to be identified [66,148,[214][215][216][217]. TPI is not the only possible technique for dental disease monitoring [218]: (i) visual caries examination, for example, loss of enamel translucency in the region between the contacting proximal surfaces of two adjacent teeth, (ii) X-ray imaging, (iii) electrical impedance measurements, (iv) ultrasound and (v) fluorescence-based methods [218,219] can also be adopted. However, many disadvantages can be assessed to some of these techniques: (i) is not possible at early detection stages, (i) and (ii) are difficult for posterior teeth, (ii) is potentially harmful for patients' health because it uses ionizing radiation.…”

“…However, many disadvantages can be assessed to some of these techniques: (i) is not possible at early detection stages, (i) and (ii) are difficult for posterior teeth, (ii) is potentially harmful for patients' health because it uses ionizing radiation. For these reasons, additional strategies for dental health monitoring, with a particular emphasis on diagnosis at an earlier stage of formation and the use of non-ionizing radiations, are widely requested [218].…”

“…Finally, in order to verify TPI validity and effectiveness in dental caries detection, Kamburoğlu et al [218] compared TPI (static images and movie video) with common radiological techniques: intraoral photostimulable phosphor late (PSP) and cone beam CT (CBCT) for the detection of dental caries ex vivo [218][219][220]. They demonstrated that TPI shows good performances for caries identification, compared to the most used techniques, see Figure 9.…”

THz: Research Frontiers for New Sources, Imaging and Other Advanced Technologies

“…TPI has been found to be an interesting technique for dental tissue (enamel, dentine and pulp) discrimination because refractive index differences enable the three tissue regions to be identified [66,148,[214][215][216][217]. TPI is not the only possible technique for dental disease monitoring [218]: (i) visual caries examination, for example, loss of enamel translucency in the region between the contacting proximal surfaces of two adjacent teeth, (ii) X-ray imaging, (iii) electrical impedance measurements, (iv) ultrasound and (v) fluorescence-based methods [218,219] can also be adopted. However, many disadvantages can be assessed to some of these techniques: (i) is not possible at early detection stages, (i) and (ii) are difficult for posterior teeth, (ii) is potentially harmful for patients' health because it uses ionizing radiation.…”

“…Finally, in order to verify TPI validity and effectiveness in dental caries detection, Kamburo glu et al [218] compared TPI (static images and movie video) with common radiological techniques: intraoral photostimulable phosphor late (PSP) and cone beam CT (CBCT) for the detection of dental caries ex vivo [218][219][220]. They demonstrated that TPI shows good performances for caries identification, compared to the most used techniques, see Figure 9.…”